Application of the Taguchi Method for Optimizing the Process Parameters of Producing Controlled Low-Strength Materials by Using Dimension Stone Sludge and Lightweight Aggregates

How-Ji Chen,Hsuan-Chung Lin,Chao-Wei Tang

doi:10.3390/su13105576

How-Ji Chen, Hsuan-Chung Lin + Show 1 more

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https://doi.org/10.3390/su13105576

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Abstract

In view of the increasing concerns over non-renewable resource depletion and waste management, this paper studied the development of low-density controlled low-strength material (CLSM) by using stone sludge and lightweight aggregates. First, the investigation was performed at a laboratory scale to assess the effects of the composition on the properties of the resulting low-density CLSM. The Taguchi method with an L9(34) orthogonal array and four controllable three-level factors (i.e., the stone sludge dosage, water to binder ratio, accelerator dosage and lightweight aggregate dosage) was adopted. Then, to optimize the selected parameters, the analysis of variance method was used to explore the effects of the experimental factors on the performance (fresh and hardened properties) of the produced low-density CLSM. The test results show that when the percentage of stone sludge usage was increased from 30% to 60%, the initial setting time approximately doubled on average. Moreover, at the age of 28 days, the compressive strength of most specimens did not exceed the upper limit of 8.83 MPa stipulated by Taiwan’s Public Construction Commission. Further, the material cost per cubic meter of the produced CLSM was about NT$ 720.9 lower than that of the ordinary CLSM, which could reduce the cost by 40.6%. These results indicate that the use of stone sludge as a raw material to produce CLSM could achieve environmental sustainability. In other words, the use of stone sludge and lightweight aggregates to produce low-density CLSM was extremely feasible.

Highlights

The continuous progress of science and technology has improved social productivity and material standard of living, and has achieved unprecedented prosperity and development of human society
The results showed that controlled low-strength material (CLSM) and wastepaper sludge ash (WPSA) could be used as backfill materials for sewage pipes, which could ensure higher stability compared with soil backfill
The fresh properties of CLSM were affected by its composition

Summary

Introduction

The continuous progress of science and technology has improved social productivity and material standard of living, and has achieved unprecedented prosperity and development of human society. Sustainability 2021, 13, 5576 raw materials for concrete production in Taiwan. For these reasons, Taiwan promulgated (amended on 21 January 2009) the Resource Recycling Act [2] on 3 July 2002, to reduce the use of natural resources, reduce waste generation, promote the recycling and reuse of materials, reduce the environmental load and build a society in which resources can be used continuously. The Ministry of Economic Affairs of the Republic of China in Taiwan has announced 57 types of industrial waste for reuse, which can be divided into engineering, agricultural and other uses. There are 22 types of recycling for engineering purposes (such as waste casting sand, stone sludge, stone waste, coal ash, waste wood, waste glass, waste pottery, waste porcelain, waste bricks, waste tiles, etc.)

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